Winter Damage to Trees in the Midwest: Prevention & Recovery

Frost Cracks and Sunscald

Frost cracks and sunscald are caused by the same fundamental mechanism: rapid temperature fluctuations on the south and southwest sides of tree trunks during late winter. On a clear, cold day, winter sunlight warms the bark surface to well above freezing while the shaded side remains frozen. When the sun sets or goes behind a cloud, the warmed tissue cools rapidly, creating thermal stress that can split the bark and underlying wood.

Sunscald kills the cambium (the living layer beneath bark) in a vertical strip on the south or southwest side. The dead bark eventually cracks and falls off. Frost cracks are vertical splits that may extend several feet and penetrate deep into the wood, sometimes with an audible crack or pop when they form. Both injuries create entry points for decay fungi. Young trees with thin bark and dark-colored bark species are most susceptible. Read more in our trunk cracks guide.

Salt Damage from Road De-icing

Road salt is a major but often overlooked cause of tree decline across the Midwest. Millions of tons of sodium chloride are applied to roads each winter, and the effects extend well beyond the pavement. Salt damages trees through two routes: aerial spray from passing traffic that coats branches and buds, and soil-borne salt dissolved in snowmelt that accumulates in the root zone.

Symptoms of salt damage typically appear in spring and early summer. On evergreens, needles brown on the road-facing side while the sheltered side remains green, creating a distinctive asymmetric pattern. On deciduous trees, leaves emerge with marginal browning (scorch), may be smaller than normal, and branches on the road side may die back progressively. Trees within 50 feet of heavily salted roads are most at risk, with damage decreasing with distance.

Heavy Snow and Ice Loading

Ice storms and heavy wet snowfall are among the most destructive winter events for Midwest trees. An inch of ice accumulation can add hundreds of pounds of weight to a tree's crown, bending and breaking branches that were perfectly sound. Heavy wet snow (the dense, packable kind) has a similar effect, especially on evergreens with dense canopies that catch and hold snow.

Species with brittle wood are most vulnerable to ice and snow damage: silver maple, Bradford pear, Siberian elm, boxelder, and black locust. Evergreens with multiple leaders like arborvitae are prone to splitting apart under snow weight. Proper pruning to remove weak attachments, reduce end weight, and eliminate co-dominant stems before winter significantly reduces ice and snow damage.

For post-storm assessment, see our storm damage guide. If trees near your home have sustained structural damage from ice or snow, contact a certified arborist for safe cleanup and risk assessment.

Desiccation of Evergreens (Winter Burn)

Winter burn is the browning of evergreen needles caused by water loss that the frozen root system cannot replace. On sunny, windy days, needles continue to lose moisture through transpiration even when temperatures are below freezing. When the soil is frozen, roots cannot absorb water to replace what is lost. The resulting drought stress kills needle tissue, which turns brown or tan.

Winter burn is most severe on the south, southwest, and windward sides of evergreens. Arborvitae, yew, boxwood, hemlock, rhododendron, and white pine are particularly susceptible. Newly planted evergreens and those in exposed locations (windy sites, south-facing walls that reflect heat and light) are at greatest risk.

Animal Damage

Deer Rubbing

Bucks rub their antlers on young tree trunks in fall, shredding and stripping bark. Trees under four inches in trunk diameter are most vulnerable and can be girdled (bark removed around the entire circumference), which is fatal. Prevention requires physical barriers: wrap trunks with hardware cloth, commercial tree guards, or chicken wire from ground level to four feet before October. Remove guards in spring to prevent moisture trapping and girdling.

Rodent Gnawing

Voles (meadow mice) and rabbits gnaw bark from the base of young trees during winter, especially when snow cover hides them from predators. Vole damage occurs at or below the snow line, while rabbit damage occurs above the snow line up to about 18 inches. Both can girdle and kill young trees. Prevention includes keeping mulch pulled back from the trunk (eliminates vole habitat), installing quarter-inch hardware cloth cylinders around the base, and maintaining short grass around trees in fall to reduce vole cover.

Spring Recovery Assessment

Conduct a thorough assessment of your trees in mid to late spring after leaf-out. At this point, winter damage is fully visible and you can make informed decisions about treatment or removal.

1. Check for dead branches: Branches that fail to leaf out are dead. Note their size and location. Remove dead branches over four inches that overhang structures or traffic areas.
2. Examine trunks: Look for new frost cracks, sunscald patches, animal damage, and salt spray damage. Document any damage with photos.
3. Assess evergreens: Brown needles from winter burn may drop naturally and be replaced by new growth from healthy buds. Wait until June before concluding an evergreen is dead.
4. Check for salt damage: Leaf scorch, stunted growth, and branch dieback on the road-facing side. Flush soil with heavy watering to leach accumulated salt.
5. Evaluate structural damage: If ice or snow caused branch breakage or trunk splits, have a certified arborist assess the tree's structural integrity.

Run a comprehensive tree health check or use our diagnosis tool to evaluate your trees after winter.

Midwest State Tree Care Guides

For state-specific tree care information, pests, and diseases affecting your area:

Frequently Asked Questions